Editor's note: Stephen Gutwillig is the California state director of the Drug Policy Alliance, an organization working to promote alternatives to the federal war on drugs.

Los Angeles, California (CNN) -- This year is a watershed year in pot politics.

The Obama administration recently announced it would defer to state medical marijuana laws and stop federal prosecutions of patients and providers who comply with them.

In California, the tanking economy inspired Gov. Arnold Schwarzenegger to call for debating marijuana taxation and regulation, a bill was introduced in Sacramento to do just that, and four separate ballot initiatives are circulating to allow voters the chance to decide the issue for themselves.

Schwarzenegger's position was echoed by New York Gov. David Paterson and by Arizona Attorney General Terry Goddard, who suggested legalizing pot could cripple Mexican and U.S. gangs. The unprecedented momentum to question marijuana prohibition is being fueled by a widely remarked-upon phenomenon -- the cultural mainstreaming of marijuana.

From Showtime's established hit "Weeds" to the "Is Pot Already Legal?" cover of Fortune magazine in September, marijuana is commanding attention and an odd kind of respect for its sheer popularity and massive revenues.

Marie Claire magazine and the "Today Show" profiled "stiletto stoners," stressed-out women professionals who unwind with a doobie instead of a cosmo. And in a recent style feature, the Los Angeles Times gushed that "cannabis culture is coming out of the closet," citing its ubiquity across the spectrum of pop culture and high-end design. "It's here to stay," the Times proclaimed.

Pot is indeed flourishing in the mainstream as never before, but the sometimes giddy discussion overlooks a sinister parallel phenomenon: More people are being arrested for pot crimes than ever; they are increasingly young and disproportionately nonwhite.

In 2008, the police arrested 847,864 people nationwide for marijuana violations, according to the 2008 FBI Uniform Crime Report. Pot arrests represent fully half of all drug arrests reported in the United States. The overwhelming majority -- a whopping 89 percent -- were charged with possession only.

Most striking, the marijuana arrest rate in the United States has nearly tripled since 1991.

More people are being arrested for pot crimes than ever; they are ... young and disproportionately nonwhite.
--Stephen Gutwillig, California state director of the Drug Policy Alliance

Examples from both coasts illustrate this. In California, according to the Center on Juvenile and Criminal Justice, crime arrest rates have generally plummeted statewide from 1990 to 2008 by an average of 40 percent. Drug possession arrests for everything but marijuana collectively fell by nearly 30 percent. But during that same 18-year period, arrests for marijuana possession in California skyrocketed 127 percent. In 2008, more Californians were arrested for pot offenses than any year since decriminalization took effect 34 years ago.

Similarly, New York state decriminalized simple marijuana possession in the 1970s. But under Mayors Rudolph Giuliani and Michael Bloomberg, New York City has become one of the marijuana arrest capitals of the world -- 40,300 arrests last year.

How can the notion that marijuana is "here to stay" coexist with these rates of marijuana arrests? Apparently because the people caught in the crossfire aren't considered part of the mainstream. In California, African-Americans are three times as likely as whites to be arrested for a pot crime, according to the Center for Juvenile and Criminal Justice. If you're young and nonwhite, you are especially targeted.

The increase in marijuana possession arrests of California teenagers of color since 1990 is quadruple that group's population growth.

In New York City, blacks and Latinos -- who represent about half the city's population -- accounted for 86 percent of everyone charged with pot possession in 2008. The NYCLU report says federal studies show young whites use marijuana at higher rates than blacks and Latinos.

Supporters of marijuana prohibition often argue that few possession busts lead to incarceration. First, that argument ignores the countless parolees and probationers sent back to jail and prison nationwide for failing drug tests or being caught with a joint. And it seriously diminishes the lifelong stigma any criminal conviction has for many young people of color, whose educational and professional opportunities are severely curtailed as a result of racist enforcement.

Getting caught with a joint means being photographed, fingerprinted and permanently entered in the vast criminal database. Apparently marijuana serves as a gateway after all, feeding young people into the criminal justice system and on to a marginalized adulthood.

Widespread discussion of everyday marijuana consumption is helping turn the tide against decades of failed marijuana prohibition. However, too much of that conversation is ignoring the people most impacted by our punitive policies.

We must end pot prohibition and stop the massive number of arrests and biased enforcement that are at its core.

The opinions expressed in this commentary are solely those of Stephen Gutwillig.